Coproduction of exopolysaccharide and polyhydroxyalkanoates from Sphingobium yanoikuyae BBL01 using biochar pretreated plant biomass hydrolysate

Sphingobium yanoikuyae BBL01 can produce exopolysaccharides (EPS) and polyhydroxyalkanoates (PHAs). The effect of side products (furfural, hydroxymethylfurfural (HMF), vanillin, and acetate) produced during pretreatment of biomass was evaluated on S. yanoikuyae BBL01. It was observed that a certain concentration range (0.01-0.03 %) of these compounds can improve growth, EPS production, and polyhydroxybutyrate (PHB) accumulation. The addition of HMF increases glucose and xylose utilization while other side products have a negative effect. The C/N of 5 favors EPS production (3.24 ± 0.05 g/L), while a higher C/N ratio of 30 promotes PHB accumulation (38.7 ± 0.08 % w/w), when commercial sugar is used as a carbon source. Pine biomass-derived biochar was able to remove 40 ± 2.1 % of total phenolic. Various biomass hydrolysates were evaluated and the use of detoxified pine biomass hydrolysate (DPH) as a carbon source resulted in the higher coproduction of EPS (2.83 ± 0.03 g/L) and PHB (40.8 ± 2.4 % w/w).